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Incidents on Oct 27, 2026

Publication date: Dates are source publication dates (JST), not occurrence dates.

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Showing 30 of 30 incidents

Incidents on Oct 27, 2026
DateTargetSummaryClassificationSource links
LEAK-650Hagi CityS 4,454,097 recordsUnauthorized access occurred in Furusato Choice, confirming the leakage of donor personal information. The leaked information includes names, email addresses, addresses, phone numbers, and hashed passwords, totaling 4,454,097 records. Currently, related services have been suspended to prevent further damage, and a detailed investigation is underway.
Unauthorized access & data leakConfirmedOfficial statement
LEAK-751Iida CityS 4,454,097 recordsUnauthorized access by a third party was confirmed at Furusato Choice, resulting in the leakage of personal information of registered donors. A total of 4,454,097 records were leaked, including names, email addresses, addresses, phone numbers, hashed passwords, and estimated donation deduction amounts.
Unauthorized access & data leakConfirmedOfficial statement
LEAK-642Rakuten TravelS Up to about 2,600,000 recordsRakuten Travel announced that unauthorized access may have led to the leakage of approximately 2,600,000 personal information records and over 36,000 card information records. It also suggested that the number of leaked records could reach 220,000,000.
Unauthorized access & data leakUnverified reportNews report
LEAK-509Sony Network Communications "So-net and plala (S course)"S 2,585,481 recordsSony Network Communications Inc. announced on October 27, 2026 that the member database of its So-net internet access service was accessed without authorization from outside on October 19 and that personal information was leaked. The company confirmed the access on October 23, stopped the affected server and blocked traffic from the source, and on October 24 identified the leaked items and counts. The leaked data comprises 2,141,986 So-net member records (1,869,771 current members and 272,215 former members who left in or after March 2026) and 443,495 plala (S course) member records (422,365 current members and 21,130 former members who left in or after March 2026), covering names, phone numbers, email addresses, user IDs, dates of birth, gender and internet connection IDs. In addition, email addresses and mailbox passwords for 54,401 addresses on Mail Service (G), A-Box, Sonet VAIO Mail and the PostPet mail account service, 16 bank account records (institution name, bank code, branch name, branch code, account type, account number and account holder name; account PINs are not held and plala (S course) members are not affected) and 7 password-reset notice records were leaked. Member passwords were not leaked and none of the data includes credit card information. No leak has been confirmed for other services, including NURO. The cause is unauthorized access by a third party and is under investigation. The company reset the affected mailbox passwords on October 27 and reported the incident to the Personal Information Protection Commission. No secondary damage had been confirmed as of October 27. Basis for the count field: the 2,141,986 So-net member records and 443,495 plala (S course) member records are summed as member records of separate services, giving 2,585,481 records. The 54,401 email addresses are described as belonging to So-net members and are not added, and the 16 bank account records and 7 notice records are also excluded from the count. This is not a number of unique people.
Unauthorized access & data leakConfirmedOfficial statement
LEAK-649Bandai Namco EntertainmentA 346,247 recordsUnauthorized access occurred to the email service of Bandai Namco ID, resulting in the leakage of email addresses of users from THE GUNDAM BASE MEMBERS. The leaked information did not include login passwords or credit card information. The number of leaked records is 346,247.
Unauthorized access & data leakConfirmedOfficial statement
LEAK-542Japan Human Resources DepartmentA 213,294 recordsUnauthorized access occurred in the email distribution service "Blast Mail," confirming the leakage of 213,294 records of email addresses. An external third party infiltrated the servers of Rakus Light Cloud and exfiltrated data. The Japan Human Resources Department stated that it will contact affected members individually and work to prevent recurrence.
Unauthorized access & data leakConfirmedOfficial statement
LEAK-512Ehime ShimbunB 32,405 recordsUnauthorized access occurred to the email newsletter distribution service "Blast Mail" operated by Ehime Shimbun, resulting in the leakage of approximately 32,405 records of personal information. The leaked information includes names, member IDs, and email addresses, while addresses and credit card information were not leaked. Currently, no secondary damage has been confirmed.
Unauthorized access & data leakConfirmedOfficial statement
LEAK-688Mos Food ServicesB 14,034 recordsMos Food Services conducted an SNS campaign in which the external tool OWNLY was accessed by a third party, resulting in the leakage of some participant information. The leaked information included usernames and user IDs, with a total of 14,034 records. Names, addresses, and credit card information were not included.
Unauthorized access & data leakConfirmedOfficial statement
LEAK-830TradeWorks Co., Ltd.C 4,975 peopleUnauthorized access occurred to the internet trading system provided by TradeWorks Co., Ltd., and customer information may have been leaked. The number of people potentially affected is 4,975 people, with an estimated loss of approximately 50,000,000 yen. The system is still operational, and no outflow of customer funds has been confirmed.
Unauthorized access & data leakConfirmedOfficial statement
LEAK-857Chitose CityC 1,141 recordsUnauthorized access occurred to Chitose City's email distribution service, confirming the leakage of 1,141 records of email addresses. According to the service provider, Rakus Light Cloud Co., Ltd., an external third party infiltrated the server and exfiltrated data. The service is currently suspended, and work is underway to resume operations.
Unauthorized access & data leakConfirmedOfficial statement
LEAK-646Hyogo PrefectureD 847 recordsHyogo Prefecture announced the possibility of a data leak involving information from participants in startup support program events. The potentially leaked information includes names and email addresses totaling 847 records.
Unauthorized access & data leakPossibleOfficial statement
LEAK-651Tokyo Fire DepartmentD 198 recordsOn October 21, 2026, unauthorized access occurred on a contractor's server, potentially leaking past recruitment exam papers and other documents. The information that may have been leaked includes 198 records, of which 1 contains the name of a staff member, while the others do not include personal information. The contractor has reported that no unauthorized data exfiltration has been confirmed to date.
Unauthorized access & data leakPossibleOfficial statement
LEAK-687Japan External Trade Organization (JETRO)D Up to 133 recordsUnauthorized access occurred to JETRO's business matching service "e-Venue," potentially leaking up to 133 records of personal information. The leaked information includes names, email addresses, phone numbers, mobile numbers, and fax numbers. The service is currently suspended, and measures are being taken to prevent recurrence.
Unauthorized access & data leakConfirmedOfficial statement
LEAK-700Chiba PrefectureF 7 recordsEmail accounts of staff and students at 7 public high schools in Chiba Prefecture were accessed by a third party, resulting in a total of 485,446 spam emails being sent. The investigation confirmed that there was no leakage of personal information. 7 records.
Unauthorized access & data leakConfirmedOfficial statement
LEAK-643Resona GroupUnauthorized access occurred to "Yumir Link" provided by Resona Group, with reports indicating a potential leak of personal information such as email addresses and customer management numbers.
Unauthorized access & data leakUnverified reportNews report
LEAK-644Kaho EnterpriseKaho Enterprise confirmed a security configuration issue in the attendance management system it operates, which may have led to the leakage of personal information of current and former employees. As of now, no external leaks or unauthorized use have been confirmed, but it is unclear whether there has been any third-party access.
Unauthorized access & data leakPossibleOfficial statement
LEAK-645JR TokaiJR Tokai announced that personal information registered in the Shinkansen reservation system was leaked due to unauthorized access from outside.
Unauthorized access & data leakUnverified reportNews report
LEAK-647Shiga PrefectureShiga Prefecture issued a warning about the possibility of personal information leakage due to unauthorized access. The methods of recent cyber attacks have become more sophisticated, raising concerns that leaked personal information could be misused. The prefecture is calling on residents to take basic precautions.
Unauthorized access & data leakPossibleOfficial statement
LEAK-648Municipalities and Government AgenciesThere were 604 cases of information leakage and unauthorized access reported in municipalities and government agencies, with a recent incident involving unauthorized access to the email distribution service of Chitose City, resulting in a confirmed leakage of 1,141 records.
Unauthorized access & data leakUnverified reportNews report
LEAK-689GMO Internet GroupGMO Internet Group was attacked by ransomware, and it has become clear that the attackers are demanding approximately 8,000,000,000 yen in payment. President Kumagai stated that they have not complied with the demands, and the attackers have also threatened to publish customer information.
RansomwareConfirmedOfficial statement
LEAK-701GiftyGifty announced that it suffered unauthorized access, resulting in the illegal issuance of approximately 550 million yen worth of "e-gifts." Additionally, Ymirlink confirmed a data leak of over 51,620,000 records, primarily consisting of email addresses, while it is still under investigation whether credit card information was included.
Unauthorized access & data leakUnverified reportNews report
LEAK-702Fukuoka PrefectureFukuoka Prefecture announced that there was unauthorized access to Sagawa Express's website related to the delivery of congratulatory messages requested by the prefecture, and that there is a possibility that personal information was leaked. The potentially leaked information includes the delivery address, name, and phone number of the congratulatory messages.
Unauthorized access & data leakPossibleOfficial statement
LEAK-715Kanagawa PrefectureA critical vulnerability in the programming language PHP was disclosed, but it was reported that there was no impact on Kanagawa Prefecture's official website or the websites of facilities it operates. The prefecture is taking appropriate measures, and some websites are temporarily suspended as a precaution. No security incidents have been confirmed.
Unauthorized access & data leakUnverified reportOfficial statement
LEAK-757GovernmentThe government is considering an emergency response package in light of the increasing damage from cyberattacks, but it is still in the dark regarding the specifics of the damage and the methods used. The number of detected cyberattacks has increased compared to the same period last year, and urgent measures are required.
Unauthorized access & data leakPossibleOfficial statement
LEAK-766Iwaki CityIwaki City has requested appropriate management from various system contractors in response to unauthorized access occurring nationwide and is confirming operational status. Currently, there are no confirmed systems with personal information leaks, but it is suggested that approximately 4,450,000 accounts may have had their information leaked in the Furusato Choice system.
Unauthorized access & data leakConfirmedOfficial statement
LEAK-819GMO Internet GroupGMO Internet Group reported a potential information leak, and a detailed investigation is underway.
Unauthorized access & data leakPossibleOfficial statement
LEAK-842FANCLFANCL's president apologized at an event regarding a data breach caused by unauthorized access. The leaked information includes 393,785 FANCL member records and 441,162 Attenir member records, with no credit card information included.
Unauthorized access & data leakUnverified reportNews report
LEAK-876ProofpointAccording to an investigation by Proofpoint, 65% of organizations affected by ransomware reported that AI increased the effectiveness of attacks. In Japan, 66% expressed a similar awareness, with 71% citing malicious attachments as the primary intrusion method. The survey was conducted among 953 cybersecurity professionals across 12 countries.
RansomwareConfirmedOfficial statement
LEAK-890Resona GroupUnauthorized access to Yumirlink's systems has been reported, potentially leading to the leakage of customer information held by Resona Group. The information that may have been leaked includes customer email addresses and identifiers, but does not include financial transaction information. A detailed investigation is currently underway at Yumirlink.
Unauthorized access & data leakConfirmedOfficial statement
LEAK-955Fukui PrefectureIn Fukui Prefecture, there have been a series of thefts of copper plates from shrines, leading to the arrest of two men involved in demolition work. The men are suspected of stealing approximately 500 kilograms of copper plates from Kabahachiman Shrine, with the rising price of copper believed to be a contributing factor.
Unauthorized access & data leakUnverified reportNews report

Showing 20 of 30 cases

Incidents on Oct 27, 2026